It is known that one of the controls which must be effected frequently and regularly in engines, of every type, such as automobiles, lorries or marine engines, of internal combustion or of Diesel type, is the control of the oil level, since, if the level of the lubricating oil is low, or positively below the minimum, the engine may undergo severe damages. It is known as well, however, that motorists are often reluctant to effect the control of oil level because it is a rather tiresome and messy operation.
On the other hand, presently available pneumatic devices for a few deluxe cars are unreliable, since the failure of a small accessory, which is rather delicate, might cause rather serious damages.
It is also to be noted that, because of the abovementioned drawbacks, most motorists entrust petrol station personnel with the control of the oil level, and these people do use rags to clean the measuring stick, these rags being oftentimes picked up from the ground. Dirt and grit is therefore likely to be introduced into the engine.